The mysterious black fungus from Chernobyl that may eat radiation
bbc.com
bbc.com
"Fungus in Chernobyl nuclear disaster zone has mutated to 'feed' on radiation (2024)" https://news.ycombinator.com/item?id=45901149 12-nov-2025
"Fungus found in Chernobyl might process radiation and act as a shield (2024)" https://news.ycombinator.com/item?id=43534021 31-mar-2025
"A Black Fungus Might Be Healing Chernobyl by Drinking Radiation" https://news.ycombinator.com/item?id=43148355 23-feb-2025
"Radiotrophic fungus" https://news.ycombinator.com/item?id=41085406 03-aug-2024
"Chernobyl fungus could shield astronauts from cosmic radiation" https://news.ycombinator.com/item?id=35181146 16-mar-2023
"Fungus at Chernobyl absorbs nuclear radiation via radiosynthesis" https://news.ycombinator.com/item?id=24166994 15-aug-2020
"Radiotrophic fungus" https://news.ycombinator.com/item?id=20342750 03-jul-2019
"Chernobyl Fungus Feeds On Radiation (2007)" https://news.ycombinator.com/item?id=6763520 19-nov-2013
"Black Fungus Found in Chernobyl Eats Harmful Radiation" https://news.ycombinator.com/item?id=127626 02-mar-2008
The reason so many were infected on Eros was because humans deliberately infected everyone on the station. Likewise with the human/protomolecule hybrids.
Like GP said, I think the trick to this book is in the relationship between the 2 main characters, so hopefully they nail that. Judging by the trailer they made it all quite humorous.
In fact, it's so good that it sets a really good example of what an enjoyable experience listening to an audiobook can be.
http://www.nausicaa.net/wiki/Nausica%C3%A4_of_the_Valley_of_...
https://ghibli.fandom.com/wiki/Nausicaä_of_the_Valley_of_the...
So "eat" was a bit of a poetic choice for the title really haha. It "eats" energy. Pretty good deal for the mold considering the radiation is going to be produced whether they "eat" it or not, for a VERY long time!
Also, making spacecraft shielding and even furniture out of this stuff? It's the stupidest thing I ever heard. The mass of the fungus doesn't come from ionizing radiation anymore than the mass of a plant comes from sunlight. You might as well claim that you're going to grow trees in space using the abundant sunlight. They power themselves with light but still need to be made out of something! Are they also hoping these fungus like to eat lunar regolith? It makes zero sense, but here we've got the BBC and apparently NASA taking the idea seriously. Where is the fucking biomass meant to come from?? I must be crazy, or they all are.
If I understand the linked NASA press releases correctly, they are talking about using a mix of regolith, cyanobacteria and fungi as part of the outer shell of a habitat. The mycelian network of the fungi binds the loose regolith together, forming a strong and somewhat flexible material, with the fungus working a bit like the cement in a concrete mix. And because fungi don't form from nothing you add cyanobacteria that create "fungus food" (presumably some sugar) from water and CO2 (I'm sure you need to add a bit more than that, but that might be beyond the scope of a press release)
This really has nothing to do with radiation-absorbing fungi at all, except for one remark how the melanin in radiation-eating fungi could provide further shielding.
Please excuse the novice question but I am confused, where does the energy come from then?
In principle if fungi could somehow concentrate enough fissionable material (say uranium), you could get something like the Oklo reactor going, but it would have to be a truly gigantic, probably unphysical amount of fungi to have access to that much environmental uranium in the first place and it would then have to be concentrated very strongly to get any measurable effect. You won't see anything at all if you just move a few atoms a few mm, so it would need to have very long range hyphae. You also need it to be basically one huge organism in order to collect the uranium to one place - billions of small fungi just doing a few square inches each won't work. It's unlikely the fungus could survive to become so huge on only the promise of fractionally higher future radiation, so it would need to eat something else too.
And then it would decay into daughter isotopes that don't further benefit from the concentration so it might not help a lot anyway if you're looking for cleanup. Plus you've covered your cleanup site in, presumably, millions of tonnes of fungus which might or might not be an improvement.
Not really. You're talking about a fungus creating essentially a nuclear reactor inside of its cells, and creating it out of fuel that's not good enough to make a nuclear reactor in the first place (it at one time was, but now it's a mess of decay products and nonsense).
Reactors also take a certain amount of mass. You can't just squish two tiny microgram particles together and hope to get anything going.
Do they? Why not?
Pretty sure
> Why not?
https://en.wikipedia.org/wiki/Critical_mass
Technically I guess I can't prove it wouldn't work if you make it dense/hot/covered-in-reflectors enough, but I'm pretty sure it's _well_ beyond the limits of what a fungus could even conceivably do.
Note that the only numbers on that page have various critical masses in kg. That's a bigass fungus.
And that's still not getting into: the "fuel" here is real shit. It's gotta be beyond its useful life even if you ignore that the thing melted down and corroded and blew up.
But the radio-active material stays in place. These fungi absorb the radiation.
Would probably require a lot more time than it would have, however, considering the relatively low amounts of radioisotopes in todays world (due to the halflife of most of them, and the age of our planet).
Several billion years ago it could have been a thing though!
The good news is radiation detectors are insanely sensitive so you can map where the hotspots are and mitigate much of the risk using exclusion zones and / or various cleanup techniques to collect the radioactive material so it can be safety stored.
Most life has evolved some sort of mechanism to control it, but sometimes it doesn’t work right.
If such a fungus existed and we had enough radioactive material lying around for it to survive, I’d expect the occasional random meltdown to occur.
Notably, this happened due to pure natural causes anyway a couple billion years ago! [https://www.iaea.org/newscenter/news/meet-oklo-the-earths-tw...]
Also interesting to see how close this fungi will grow to the radiation source, or will it be able to mutate to completely envelop the radiation source.
Energy source is still heated water.
Me - Nov 28, 2025, 10:51 AM:
Hey Dr. Dadachova, there was an article in the bbc today about radiotrophic fungus, I did some reading on them and it got me thinking about vitiligo. Current dermatology literature focuses on the immune destruction of melanocytes, often citing "oxidative stress" as a cause. However, there seems to be a total absence of data regarding the physical structure of the melanin polymer itself in these patients.
re: your findings that melanin’s electronic structure (EPR signal) changes under stress to become "protective/radiotrophic," I am wondering if the inverse mechanism could be driving vitiligo, where the melanin polymer is structurally defective (acting as a pro-oxidant "leaky capacitor") rather than a protective shield?
To your knowledge, has anyone ever applied the EPR techniques used in your fungal research to analyze melanin isolated from the active border of Vitiligo lesions? It seems plausible that a structural defect in the polymer physics could be the upstream trigger for the autoimmunity, similar to the "toxic melanin" theories in Parkinson’s disease.
I realized this sits at the exact boundary of your expertise in melanin physics and clinical pathology, and I was curious if you had ever explored this link??
tnx for reading! have a great weekend! :)
j.
--
Dadachova, Kate Fri, Nov 28, 9:57 PM to me
Hello John,
Thank you for your message and interest in melanin work! We have never looked at melanin in Vitiligo lesions but I think that your hypothesis about defective melanin could be correct. I know that there are studies showing absence of EPR signal in Vitiligo, and, on the contrary, enhanced melanin signal in melanoma in comparison with benign nevi. Probably an interesting study for a pathologist to perform!
Best regards,
Kate
Wouldn't that be very easy to measure? My guts tell me that using the melanin as a shield against gamma radiation has a negligible effect, if any at all.
But how about the theory that systems to clean up smashed up proteins from UV light is also good to clean up smashed up proteins from gamma radiation?
And one of the parts of that system, or upregulated with that system, is melanin.
Even if it did somehow accelerate the decay, it wouldn't be that useful, since (Chernobyl aside), all the waste from the typical civilian nuclear reactor can fit in a side lot on the site of the reactor complex itself (and often does!). There just isn't that much radioactive waste to clean up!
Not to disagree with you, just to say that even though it's a minor nuisance it nevertheless occupies a lot of mental space because of how annoying it is.
A radiotropic fungus that’s in TFA can’t meaningfully affect the rate at which nuclear decay is happening. What it can do, supposedly, is to harvest the energy that the nuclear decay is releasing; normally there’s too much energy for an organism to safely handle.
At the risk of vastly oversimplifying, you can’t plug your phone into high voltage transmission lines. These fungi are using melanin to moderate the extra energy, stepping it down into a range that’s useful (or at least minimally harmful).
- If we assume they are working in the reactor we get radiation levels of something like 1 mGy/hour. But we can prop this up to mabye 500 mGy/hour since i dont know how they grew their culture
- That leads to 0.05 J of extra energy per gram of microbial bio material.
- Energy needed to grow 1g of microbial biomaterial ≈ 3.15 kJ 10% of that is 315 J per gram
The result is that:
The amount of radiation energy available is 4 orders of magnitude too small to power even a 10% growth boost.
Edit: updated with more accurate estimations.
The world rejoices as this fungus is perfect for cleaning up nuclear waste products, until we realize that it evolved to function outside of Chernobyl and begins to eat everything it can reach. Mankind launches into a desperate struggle for survival as the fungus lays waste to large swathes of land.
[Assuming they use the radiation to get energy [1].] They just wait patiently until the radioactive atoms decay and emit radiation, like a gamma ray, and then absorb the gamma ray and use the energy. The half life of the radioactive material does not change.
[1] I still doubt this claim, but let's go along assuming the best case.
Armillaria ostoyae ( https://en.wikipedia.org/wiki/Armillaria_ostoyae )
Consider when organisms must pass, that these ancient fungi likely still consume the host... Thus, on a 8000 year timescale most fungi doesn't necessarily need to pursue food that naturally dies in around a century.
Yeasts are already sharing your body along with numerous other organisms that are often harmless or even beneficial. Best not think about it too much if you are uncomfortable with seeing yourself as a mini ecosystem. =3
My summary after wondering why you chose the word "consume".
https://en.wikipedia.org/wiki/Armillaria_ostoyae
rivals the aspen grove "Pando" as the known organism with the highest living biomass and perhaps rivalled by a colony of Posidonia australis on the Australian seabed that measures 200 square kilometres (edited)But I am going to add it to the Gray Goo wiki page under "in popular culture".
Don't wait to write sci-fi I suppose! Life may catch up, haha.
It can concentrate radionuclides, but the step function after inducing some criticality is likely to cause reproductive difficulty (stopping fungus evolution).
Plus: heavy metals combined with organics have a tendency towards being nasty poisonous
Just write it if you want to.
I do know that when I write it it'll be a different take, because it'll be my voice and perspective and a synthesis of the media that makes me, me.
But as they say, writing is hard. :)
My parent comment deals more with the idea that some fantastical sci-fi ideas or inventions become less fantastical the longer you sit on them. The idea for a touch-based slate computer in TNG was pretty cool! Now everyone has a tablet, and that took only about 20 years.
I don't believe other literary genres have this unique problem. If I came up with a Game of Thrones-esque fantasy story, I wouldn't need to worry about the worldbuilding becoming "outdated." (Maybe in esoteric cases like dinosaurs not having feathers before we discovered that they do, etc.)
There's all sorts of memes about SciFi films that borrowed ideas and motifs from earlier works... but often when you did, it comes out that the earlier works also borrowed those pieces.
Unfortunately and / or fortunately thanks to AI tech, anyone with an idea can now throw it at an AI and see it materialise.
For example:
> Energy needed to grow 1g of microbial biomaterial
based on what?
Edit: Maybe you meant that radiation alone wouldn't be enough for that growth, so there'd be other components that it's helping with.
- Negentropy concept revisited: Standard thermodynamic properties of 16 bacteria, fungi and algae species ( https://arxiv.org/abs/1901.00494)
> Maybe you meant that radiation alone wouldn't be enough for that growth, so there'd be other components that it's helping with.
Yes. Clearly it grew as it grew, but the question is what drove/powered the growth.
Don't do this, and don't then share the resulting numbers as fact publicly without disclosing you just asked a chatbot to make up something reasonable sounding.
If the chatbot refers to a source, read the source yourself and confirm it didn't make it up. If the chatbot did not refer to a source, you cannot be sure it didn't make something up.
The property measured in the source you linked, "enthalpy of formation", is not the same as the energy required to grow 1g of biomatter. One clue of this is that the number in the paper is negative, which would be very strange in the context you requested (but not in the context of the paper). For the curious: "A negative enthalpy of formation indicates that a compound is more stable than its constituent elements, as the process of forming it from the elements releases energy"
You're feeding yourself (and others) potentially inaccurate information due to overconfidence in the abilities of LLMs.
I hear you.
It was really just food for thought.
They are almost completely unrelated concepts. The enthalpy of formation from the paper is the free useable energy that would be generated if you assembled all the molecules in the biomatter from the constituent atoms. E.g. the energy that would be released if you took pure hydrogen and pure oxygen and combined it into 1 gram of water. But the fungi takes in water from the environment to grow, it does not make it's own water from pure hydrogen, and it certainly does not generate any free energy from growing larger. With some margin for error in my understanding, since I'm not a chemist (but neither are you, and neither is the chatbot).
> It was really just food for thought.
It was more poison than food, since you just parroted randomly generated misinformation from the chatbot and passed it of as authentic insight.
The core idea was not generated from a chat bot. Neither was the article i gave (that was my own googling).
The core idea (that there is a requirement and a availability of energy that may differ) was generated from my brain not that i personally think the origin of an idea matters to its value.
What if for some reason gamma radiation changes the equilibrium constants for ADP --> ATP?
E.g. Could be denaturing something else, unlocking a previously inaccessible energy source. Possibly some radiochemistry creating a new food source for the fungus too.
No, the elephants foot isn’t a point source at its surface.
To use an extreme example going from 1m away from the sun to 100m away from the sun doesn’t result in a 10,000x drop off in energy density. Instead the exponential drop-off occurs relative to the center of the sun because energy is coming from any point on the surface visible to that location. A similar principle applies with the elephants foot, though the geometry is more complicated.
As to a point source, if you’re making an approximation use the center of the object and your 100m distance calculation would be corrected by about 25x. Though obviously the building itself provides shielding.
In the end, I'm not sure what your point is? Are you disagreeing with my overall estimate that the energy produced by the elephant's foot's radioactivity at 100 meters distance is one billion times lower than the energy we receive from the sun, and therefore fungi can't "feed" on it, because this energy is nowhere near enough to sustain life?
[1]https://en.wikipedia.org/wiki/Elephant%27s_Foot_(Chernobyl)#...
Yes, the elephants foot is not the only radiation source at Chernobyl making your calculation meaningless in practice.
You’re making such a huge range of incorrect assumptions here and I was trying to correct some of them. I’m honestly done with this conversation but it’s worth remembering that order of magnitude calculates can be off by 100,000 fold when you make the wrong assumptions.
Also, Wikipedia itself says the reading was from 8 months after the accident. “At the time of its discovery, about eight months after formation, radioactivity near the Elephant's Foot was” The falloff from 8 months post accident to now isn’t actually that large because even iodine 131 had already seen 30 half lives at that point the really nasty stuff was already gone and the reasonably long lived stuff is what was left.
Finally, fungi get by on way less energy than plants do from photosynthesis it’s really not a particularly meaningful benchmark.
Over what timeframe? If that’s 0.05 J per hour and “the researchers found that fungi that faced the galactic cosmic radiation for 26 days grew an average 1.21 times faster” 26 * 25 / 21% and the numbers don’t look that unreasonable.
But i focused on the 10% mentioned.
That said time could be factored out if you did everything properly.
It has not actually been proven that this fungus gets energy from the radiation itself. They simply observe it growing faster in the presence of radiation which could be caused by any number of other things.
https://en.wikipedia.org/wiki/Ionizing_radiation
Ionizing (or ionising) radiation is particle or photon that has enough energy to detaching electron from atoms or molecules. It includes all the usual high energy radiations such as Gamma, X-rays, high energy UV, alpha, beta, neutron et al. HN high energy physicists can correct me, sounds like it is not any particular category of the harmful radiation from a nuclear disaster, it is all of them.